Assigning Coordinates to a 3D Map Dwg.?

[jo_rizoe]

I am having trouble getting my coordinates system to "stick". I have gone under Map - Tools - Assign Coordinate System, but it does not seam to "stick". I also have trouble getting my DXF files to match with my drawing coordinates. How can I make sure both my drawing and Imports are all on the same coordinate system. I usally work with NAD 83 Zone V in feet. Can anyone help?

[Jmurphy]

Are you selecting the coordinate system code or just typing the coordinate system in the text box? Do you mean NAD83 Zone 5 ( MTM83-5IF )?